Missing Piece Illusion - Square

Lately my son and I have been playing with brain teasers and optical illusions and we came across this illusion recently on the internet.

Essentially, you've got 5 pieces that fill a specific area. You take one piece out, but the remaining four still fill the same area? Of course not, and it is an optical illusion which exploits our brain's inability to perceive small differences. 

This illusion is nothing new. But I just I decided to make a simple 3D model for my son to play with his friends.

Printing

Please note that I have uploaded two versions. One version has the holes for 6x3 magnets whereas other one doesn't have any magnet holes. Non-magnet version also makes it a simple puzzle for kids.

Print 4 copies of “Border Piece x4” and 1 copy of “Center Piece”.